Electrostatic treatment of oil and water has been used by the oil industry for many years to aid in the separation of water from an oil-continuous stream. Treating a water-in-oil emulsion by passing it through a high voltage electrostatic field has been shown to promote rapid coalescence of the water droplets leading to rapid separation. Electrostatic voltage sources includes AC, DC and combined AC/DC.
For background information relating to the basic subject matter of this invention, reference may be had to U.S. Pat. Nos. 4,601,834 and 4,747,921, and to pending U.S. patent application Ser. No. 08/381,196 entitled "METHOD AND APPARATUS FOR OIL/WATER SEPARATION USING A DUAL ELECTRODE CENTRIFUGAL COALESCER", filed 31 Jan. 1995. These two patents and the application are incorporated herein by reference. For further background information, reference can be had also to the following patents:
______________________________________ PATENT NO. INVENTOR TITLE ______________________________________ PCT WO 92/05853 Bailes et al Separation of the Components Of Liquid Dispersions EPC 0 617 115 A1 Prevost et al Dipositif et proceded de separation de phases de densites et de conductivites differentes par electrocoalescence et centrifugation 1558382 Marx Electrocentrifugal Separation 1565997 Girvin Centrifugal Dehydrator 3758399 Pendergrass Pulse Imparter 4116790 Prestridge Method and Apparatus For Separation of Fluids With An Electric Field and Centrifuge 4341617 King Liquid Treater Having Electrical Charge Injection Means 4601834 Bailes et al Settling of Liquid Dispersions 4801370 Arnesen Field Generator For Generating An Electrostatic Field In A Body Of Liquid ______________________________________